Does a separate Dac recieve raw data from transpor

Ladies and Gentlemen how does a separate Dac receive music information from a CD transport? For example, if the transport has an on board DAC does the separate DAC have to use that already processed information or is there some way it can receive unaltered info to process on its own?
A CD player used as a digital transport will simply bypass its own D/A conversion circuitry and send raw digital data to the outboard dac.
My Krell SACD Standard mk III allows the option to select RAW or PCM in one of its menus. I didn't know what these meant but had seen PCM before somewhere, so I chose PCM. I use it now as a transport, previously as a player.